I learned this fact, after substantial research, from Microsoft itself.
So, I am trying to make this work. First, I fired up Visual Studio and created a new project, Hello World!! I tell it to show me the site, it calls the web browser with a long port number, ie, localhost:1234859. It works. Life is good.
I head over the IIS control panel, following the instructions. The basic premise is that you find an item called Sites, tell it to add a new one, and enter some info. I take a look at the default website and figure out what folder to refer to. After a couple of tries, I have an item that looks mighty good.
I try it and get "Firefox can't find the server at www.sandbox.local."
Thinking that there might be something wrong with my site, I revise the entry to point to inetpub/wwwroot. No dice. Lots of other random stuff. No dice.
There is something called "Pass Through Authentication" which has a 'Test" button on the configurator. It doesn't pass. I think that, tomorrow, I will investigate this.